Noise-muffler for exhaust-pipes.



D. W. DUDDERAR. NOISE MUFFLER FOB EXHAUST PIPES.

APPLIOATION FILED MAR. 31, 1910.

Patented Feb. 21, 1911.

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UNITED STATES PATENT OFFICE. v

DANIEL W. DUDDERAR, OF MOUNT AIRY, MARYLAND.

NOISE-MUFFLER FOR EXHAUST-PIPES esasao.

Specification of Letters Patent. Patented Feb. 21, 1911.

' Application filed March 31, 1910. Serial No. 552,543.

following is a specification.

This invention relates ,to a device for muffling the noise of exhaustpipes.

The object of the invention is to provide means whereby some portion ofthe exhaust gases of an internal combustion engine may flow through apassagedirect to the atmosphere, and other portions of the gases befirst diverted into a chamber and after expanding in said chamberreturnto said direct passage where such expanded gases will serve as anelastic hindrance to retard the escape of other unexpanded gases. Thussome of the exhaust as itself is used as an elastic or yielding ba e.

Referring to the annexed drawingFigure 1 is a vertical longitudinalsection of the noise mufller on the line 11 of Fig. 2. Fig. 2 is across-section on the line 2.2 looking downward. Fig. 3 is a View of abroken portion of the deflectingtube spread into a flat form.

The size of the'exhaust tube relative to the size of the muflier shellis indicated in thedrawing; the exhaust tube, 1,-leadin from the enginemay be of any preferred size, say three inches. The outsideshell, 2, ofthe mufliep chamber is cylindric; this shell hasa bottom head, '3, and atop head, 4; each head may have a circumferential flange, 5, by whichitis secured to the cylindric shell, 2, and may be fastened in anyapproved manner. The exhaust tube, 1, may

4 be attached to the bottom head, 3, by means of a flange, 6, or anyother preferred construction. The terminal or discharge end,

1", of the exhaust tube may be attached to the top head',.4=, by acollar, 7 ,or otherpre ferred construction.

It. will be seen that the exhaust tubes, 1, and, 1*, do not ofthemselves constitute a ,conti'nuous passage through the mufller .shell,2..

The mufller shell, 2, contains a defliniting tube, 8, extendinglengthwise of the shell and secured in concentricposition therein; thediametric size of the deflecting tube, 8', is greaterthan that of theexhaust tube, 1, and

the lowermost end of said deflecting tube where it is secured to thebottom head, 3, surrounds the opening therein where the said exhausttube is attached.

The deflecting tube, 8, forms inside of the shell, 2, a central mixingand bafliing chant her, and also forms a space around said centralchamber which space constitutes an ex-.

panding chamber, 9. The said deflecting tube, 8, is cylindric and isprovided with two series of holes or ports,.10, 11; and two series ofinward-projecting diver-ter tongues, 12, 13. The series of holes,.10,and inclined tongues, 12,-are formed in the upper part of the cylindrictube, 8, and these tongues all point in the direction .opposite that inwhich the exhausting gases are moving to escape to the atmosphere asindicated by the darts, 14. An inclined tongue, 12, is over each hole,10. The other series of holes, 11, and tongues, 13, are in the lowerpart of the tube, 8, but the lower tongues, 13, are inclinedreverselywith respect to the upper tongues, 12; the ends of these lower tonguesall point in the same direction in which the exhaust gases are moving.Although all of the tongues project inwardly within the tube, 8, yetthere is left a clear straight passage directly through the center ofthe tube, which clear passage has the same diameter as the exhaust tube,1, and, 1.

The Wall of the tube, 8, may have as many rows of holes and inclinedtongues as the designer may prefer. In Figs. 1 and 2 four rows areindicated; .but in Fig. 3, the broken and flattened portion, 15, isintended to show just one half of the cylindric tube and has three rowsof holes and tongues. It will be observed in Fig. 3 that the holes, 10,in one vertical row are placed opposite the spaces which are betweentheholes in the next'adjoining rows- While such an arrangement ordisposition of holes is Jde'em'ed a good one, it is obvious otherarrangement of holes maybe made that will be eflective.

-The bottom head, 3, of the mufller shell.

'pipe or tube, 1, and enter the deflecting tube, 8, passing by thelowertongues, 13,.

i which point in the same direction in which expanded gases serve as anelastic baflle when they 'meet other unexpanded gases coming through thetube, 1, and the latter gases will be hindered or retarded thereby. Assome portion of the gases is always free to escape to the atmosphere atthe discharge tube, 1, the operation of escaping is continuous and notbypuffs. This particular operation is effective and has not heretoforeto my knowledge been employed.

The operation herein described of employinf within the tube, 8, some ofthe expande gases to serve as an elastic bafile to retard the escape ofother exhaust gases, may be produced in practical degree without havingthe inclined tongues, 12, and, 13, mere holes, 10, and, 11, beingoperative.

Having thus described my invention what I claim and desire to secure byLetters Patent is,-

l. A noise-muffler for exhaustipes having in combination a shell provied with a bottomand top head and an outlet in the top; a deflecting tubeinside of the shell and extending lengthwise thereof and forming withinthe shell and around the tube an expanding chamber, and the lower end ofsaid tube surrounding the central inlet-opening and being diametricallylarger than said opening, and said tube provided with two series ofports, 10, 11, and two series of tongues, 12, 13, which inclineinward1yone tongue being over each portthe series of tongues in theupper art of the said tube pointing in the direction of the saidinlet-opening, and the series of tongues in the lower part pointingreversely with respect to the tongues in the upper part, all of saidtongues leaving a clear, direct passage through said tube, and anexhaust pipe attached to the said bottom head around said inlet-openin2. A noise-mu er for exhaust ipes having in combination a shell provi edat one end with a head having a central inlet-opening to receive theexhaust gases from an engine and at its other end with a head having anoutlet to the atmosphere; a tube inside of said shell and having one endcommunicating with the said inlet-opening and its opposite endcommunicating with saidoutlet to the atmosphere and forming around thetube and within the said'shell an expanding chamber,said tube providedwith numerous holes communicating with said expanding chamber; and anexhaust pipe communicating directly with said inletopening, whereby someportion of the unexpanded gases may pass from the inlet-opening throughsaid tube directly to the outlet that opens to the atmosphere, whileother portions of the gases will be diverted from the inside tubethrough the holes therein into the expanding chamber and there expandedand then pass back into the said inside tube where they serve as anelastic baffle to momentarily retard the escape of some'portion of theunexpanded gases.

In testimony whereof I aifix my signature in presence of two witnesses.

DANIEL W. DUDDERAR. Witnesses:

S. R. CAmNs, JOHN HOWELL.

